Growth control device

ABSTRACT

A growth control device includes a bone plate having a stepped profile defined by a first level, a second level and an intermediate ramp connecting the first and second levels. The first level includes a first threaded hole for receiving a first bone fastener and the second level includes a second threaded hole for receiving a second bone fastener. The bone plate includes a proximal pair of side female notches, a distal pair of side female notches, a proximal guide hole and a distal guide hole.

INTRODUCTION

Various devices are known for correcting bone deformities in pediatricor other patients.

The present teachings provide a growth control device that can be usedfor correcting bone deformities.

SUMMARY

The present teachings provide a growth control device. In one aspect thegrowth control device can include a bone plate having a stepped profiledefined by a first level, a second level and an intermediate rampconnecting the first and second levels. The first level can include afirst threaded hole for receiving a first bone fastener and the secondlevel can include a second threaded hole for receiving a second bonefastener. The bone plate can include a proximal pair of side femalenotches, a distal pair of side female notches, a proximal guide hole anda distal guide hole.

In another aspect, the growth control device can include a bone plate asabove, first and second bone fasteners receivable in the first andsecond holes and angulatable relative to an axis substantiallyorthogonal to the bone plate within a cone of angulation, and a holdingdevice having first and second arms pivotable relative to one another,and first and second legs extending from the first and second arms. Thefirst and second legs have first and second distal ends defining acurved split slot and a pair of male notches extending from a lowersurface of the split notch, the first and second male notches engagingthe first and second female notches when one of the proximal or distalends of the bone plate is held in the curved split slot.

In a further aspect, the growth control device can include a pluralityof bone plates of different sizes, each bone plate having first andsecond threaded holes and an intermediate portion between the first andsecond holes, the intermediate portion having a third threaded hole. Theplurality of bone plates can include at least one stepped bone platehaving an intermediated portion in the form of a ramp, and at least onearched bone plate having an intermediate portion in the form of a curvedarch.

Further areas of applicability of the present teachings will becomeapparent from the description provided hereinafter. It should beunderstood that the description and specific examples are intended forpurposes of illustration only and are not intended to limit the scope ofthe present teachings.

BRIEF DESCRIPTION OF THE DRAWINGS

The present teachings will become more fully understood from thedetailed description and the accompanying drawings, wherein:

FIG. 1 is a perspective view of a growth control device according to thepresent teachings;

FIG. 2 is a top view of the growth control device of FIG. 1;

FIG. 2 is an elevated side view of the bone plane of FIG. 1;

FIG. 3 is a perspective view of a growth control device according to thepresent teachings;

FIG. 3A is a top view of the growth control device of FIG. 3;

FIG. 4 is a perspective view of the growth control device of FIG. 1shown with a holding device;

FIG. 4A is an enlarged detail of FIG. 4;

FIG. 4B is an enlarged detail of the holding device of FIG. 4;

FIG. 5 is a perspective view of the growth control device of FIG. 1shown with a holding device;

FIG. 6 is an elevated side view of the growth control device of FIG. 1shown with a targeting device;

FIG. 7 is a perspective view of the growth control device of FIG. 1shown with a holding and targeting devices;

FIG. 8 is an environmental view showing a growth control deviceimplanted in the femur and a growth control device implanted in thetibia according to the present teachings;

FIG. 9 is an elevated side view of the growth control device of FIG. 1shown with variable-angle bone fasteners;

FIGS. 10-18 are views illustrating various aspects of implanting agrowth control device in the tibia with associated devices according tothe present teachings;

FIG. 19 is a perspective view of a growth control device coupled to anextractor according to the present teachings; and

FIG. 19A is an enlarged detail of a distal end of the extractor of FIG.19.

DESCRIPTION OF VARIOUS ASPECTS

The following description is merely exemplary in nature and is in no wayintended to limit the present teachings, applications, or uses. Forexample, although the present teachings are illustrated for proceduresrelating to femur and/or tibia, the present teachings can be used forany long bones in pediatric or other surgery. In particular, the presentteaching can be used to correct angular deformities in long bones inpediatric patients.

Referring to FIGS. 1-8, various aspects of exemplary growth controldevices according to the present teachings is illustrated. The growthcontrol device can include one or more bone plates 100. A bone plate 100can have an anatomically contoured stepped or offset profile, asillustrated in FIGS. 1, 1A and 2, or an anatomically contoured humped orarched profile, as illustrated in FIGS. 2 and 3. An environmental viewof anatomically contoured bone plates 100, as implanted in the femur 80and tibia 90 according to the present teachings, is illustrated in FIG.8.

Generally, the growth control device can be used to provide gradualcorrection of an angular deformity in a long bone by restraining oneside, medial or lateral, of the growing bone, causing the bone to growon the opposite side, thereby forcing a natural correction by anon-symmetric corrective bone growth. Further, as illustrated in FIG. 8,the growth control device can include a bone plate 100 which iscontoured and profiled for matching the anatomy of the particular bone,and non-locking threaded bone fasteners 150 that can angulate about anaxis C perpendicular to the bone plate 100 within a cone of maximumangulation of an angle β of about 32-degrees between axes C′ and C″, asshown in FIG. 9. Each bone fastener 150 can be cannulated therethroughfor receiving a guide wire 300, and can have a spherically shaped head152 including a formation for engaging a driver 320, as shown in FIG.18. The bone fasteners 150 can be low-profile cannulated titanium alloyscrews with self-cutting tips and reverse buttress threads to guardagainst pull out.

More specifically, and referring to FIGS. 1, 1A and 2, the bone plate100 can have, in a side elevated view, a stepped profile 116 thatincludes a first level 120, a second level 122 and an intermediateinclined or ramped portion 118 connecting the first level 120 to thesecond level, as shown in FIG. 2. The profile 116 can be shaped toconform to the anatomic contour of a long bone of a patient and can beprovided in various sizes and shapes, including the relative dimensionsof the first level 120, the second level 122 and the intermediateportion 118, to account for anatomic differences from bone to bone andfrom patient to patient, including patient's age, gender, and degree ofdeformity. The first level 120 and the second level 122 can be disposedin parallel and spaced apart planes.

Referring to FIGS. 1-2, 4-7, 19, and 19A, the bone plate 100 can includefirst and second (proximal and distal) holes 102, 104 extending throughthe thickness of the bone plate 100 from an outward or upper surface 111to an opposite bone-engaging surface 113. The holes 102, 104 definecorresponding inner surfaces 103, 105, which are threaded andspherically shaped for receiving threaded fixation bone fasteners 150having spherically shaped heads 152, as shown in FIG. 9. The bone plate100 can also include a third or central hole 106, positioned between thefirst and second holes 102, 104. The third hole 106 can define athreaded inner surface 107 for engagement with a threaded distal end 408of a post 400 of a targeting device and/or a threaded distal end 352 ofan extractor 350, as shown in FIGS. 6, 7 and 19. Further, the bone plate100 can include two smaller end openings or guide holes 112 at theproximal and distal ends of the bone plate 100 for guiding a K-wire orother guide wire 300 therethrough, as shown in FIG. 5, for example. Thebone plate 100 can also include two pairs of female side notches 110,i.e., medial and lateral notches 110 at the proximal and distal ends ofthe bone plate 100, for engagement with forceps or other holding device200, as shown in FIGS. 4, 4A, 4B, for example, and described below.

Referring to FIG. 2, the bone plate 100 can include first and secondwashers 130 surrounding the first and second holes 102, 104 on the boneengaging surface 113 of the bone plate 100. Each washer 130 can beunitarily integrated and built-in the bone plate 100 forming a unitarydevice with the bone plate 100. The washers 130 can provide a clearancefor the physis of the bone and reduce contact with the periosteum of thebone.

In another aspect, and referring to FIGS. 3 and 3A, a bone plate 100having an intermediate portion 119 in the form of an arch or hump,rather than an offset ramp, can be used depending on the anatomicalcontour of the specific patient or long bone. The intermediate portion119 avoids placing bearing load on the physis of the bone or injuringthe physis during the correction period, when the bone plate 100 isimplanted in a pediatric patient for correcting a non-symmetric growthor other unequal bone growth or deformity. In other respects, the boneplate of FIGS. 3 and 3A is similar to bone plates of FIGS. 1-2.

The profile 116 of ramped bone plate 100 of FIG. 2 can match theanatomical features of the proximal tibia 90 before the bone fastenersare implanted through the bone plate 100. Further, the ramped profile116 allows parallel placement of bone fasteners 150 through the holes102, 104 of the bone plate 100, as shown in FIG. 8. Gradual angulationof the bone fasteners 150 relative to the bone plate 100 occurs over alonger period of time before reaching the maximum angulation of thegrowth control device. The extended period to maximum angulation canreduce the risk of bone fastener fracture, which can be greater whenmaximum angulation of the bone fastener 150 is reached such that thegrowth control device of the bone plate 100 and the bone fasteners 150becomes substantially rigid while bone growth continues.

The combination of the stepped profile 116 and other features of thebone plate 100 of FIG. 2 with the ability of the bone fasteners 150 toangulate relative to an axis C perpendicular to the bone plate within acone of angulation of an angle D can provide deformity correction duringthe physis growth period without closing the physis or completelypreventing growth until maximum angulation is reached.

Various devices can be used for implanting the bone plate 100 and thebone fasteners 150, for interoperative manipulation of the bone plate100 and for bone plate extraction. Referring to FIGS. 4, 4A, 4B and 5, aholding device 200 for the bone plate 100 in the form of forceps isillustrated. The holding device 200 has scissor-like gripping handles216, first and second arms 212, 214 pivotably coupled with a pivot pin210, and first and second legs (forceps tips) 202, 204 configured forholding the bone plate 100 from one end, and capturing a guide wire 300that can pass through the corresponding end opening 122 of the boneplate 100. The distal ends of the forceps legs 202, 204 define a splitcurved groove or slot 230, in the form of a pair of slots 230, betweencorresponding upper and lower surfaces 232, 234. A pair of male notchesor press pins 240 extend from the lower surface 234 substantiallyperpendicularly to the lower surface 234 and up to or stopping justshort of the upper surface 232 of the slot 230. The split slot 230 isshaped to receive either end of the bone plate 100, such that the pins240 engage the side notches 110 of the bone plate 100. The pins 240 cansecure the bone plate 100 to the holding device 200 and preventunintentional shifting of the bone plate 100 during tightening of thebone fasteners 150. The distal ends of the legs 202, 204 also define asplit guiding bore 242 for receiving the guide wire 300 that passesthrough the end hole 112 of the bone plate 100 and between the legs 202,204 of the forceps when the bone plate 100 is held in the slot 230 ofthe forceps 200, as shown in FIGS. 4A and 4B. The first and second legs202, 204 of the holding device 200 can be contoured and cooperate withthe spilt guiding bore 242 to provide an integrated guide for the guidewire 300 along the length of the legs 402, 404, as shown in FIG. 4A.

Referring to FIGS. 6 and 7, a targeting device 400 can be used forguiding the angulating bone fasteners 150 through the bone plate 100.The targeting device 400 can include a support bar or plate 406 havingopenings for receiving a support post 404 along an axis A and a tubularor cannulated drill guide 402 along an axis B at an angle a of about 16degrees relative to the axis A, corresponding to a cone of maximumangulation of 32 degrees. The drill guide 402 can include a proximal endwith an engagement formation for driver-assisted placement. The supportpost 402 can have a threaded distal end 408 threadably engaging thethreaded third hole 106 of the bone plate 100. The extractor 350illustrated in FIGS. 19 and 19A can be used as the support post 402. Thetargeting device 400 can be used with the holding device as shown inFIG. 7.

The growth control device can be provided in the form of a surgical kitincluding a plurality of bone plates 100 of different sizes andgeometries with an arched intermediate portions 119 or a rampedintermediate portion 118, a holding device 200, a targeting device 400with different size drill guides 402, a plate extractor 350, variousguide wires 300 and drill bits and other instruments, such as an impacttrocar, a ratcheting wrench, a torque driver, and the like.

Referring to FIGS. 10-18, an exemplary surgical procedure for implantingthe growth control device is illustrated. Referring to FIG. 10, a guidewire 300 can be inserted in the physis (growth plate) of the tibia 90.The bone plate 100, as held by the holding device 200 and with proximaland distal drill guides 402 engaging the corresponding first and secondholes 102, 104 of the bone plate 100, can be passed over the guide wire300, such that the guide wire 300 passes through the third hole 106 ofthe bone plate, as shown in FIGS. 11 and 12. Alternatively, if placementof a guide wire 300 into the physis is to be avoided, the guide wire 300can inserted proximally or distally off the physis and received throughthe corresponding proximal or distal end hole 112 of the bone plate 100,as shown in FIG. 4A.

Another guide wire 300 is inserted into the proximal drill guide 402, asshown in FIG. 12, and the bone is drilled with a cannulated drill bit302 placed over the proximal guide wire 300, as shown in FIG. 13. Anappropriately sized bone fastener 150 can be selected and passed overthe guide wire 300 using a driver 320 engaging the head 152 of the bonefastener 150, as shown in FIG. 14.

The procedure can be repeated for the distal bone fastener 150. A distalguide wire 300 can inserted through the distal drill guide 402, as shownin FIG. 15, and the holding device 200 can be removed, as shown in FIG.16. A drill hole can be prepared for the distal bone fastener 150 with adrill bit 302 over the distal guide wire 300, as shown in FIG. 17, andthe distal bone fastener 150 can be passed over the distal guide wire300 and seated through the bone plate 100 into the tibia 90 with adriver 320, as shown in FIG. 18.

Although the implantation procedure is illustrated for the tibia, a boneplate 100 can be similarly placed on the femur, as shown in FIG. 8. Ascan be seen from FIG. 8, the initial placement of the bone fasteners 150in each bone plate 100 can be such that the bone fasteners aresubstantially parallel or have a minimum amount of angulation to reducethe risk of breakage, as discussed above. The arched or stepped geometryof the bone plate 100 permits minimal contact with the lateral physis,as shown in FIG. 8, and can reduce the risk of pressure necrosis.

Referring to FIGS. 19, and 19A, the bone plate 100 can be removed withthe extractor 350 after the bone fasteners 150 have been unscrewed andremoved with a driver 320. The distal end 352 of the extractor 350 caninclude threads 354 engageable to the threaded inner surface 107 of thecentral hole 106 of the bone plate 100 for capturing and removing thebone plate 100. The distal end 352 of the extractor 150 can have acutting flute 356 for passing through fibrous soft tissue and a curvedtip 358 defining a non-invasive radius for avoiding accidental damage tothe physis.

The foregoing discussion discloses and describes merely exemplaryarrangements of the present teachings. Furthermore, the mixing andmatching of features, elements and/or functions between variousembodiments is expressly contemplated herein, so that one of ordinaryskill in the art would appreciate from this disclosure that features,elements and/or functions of one embodiment may be incorporated intoanother embodiment as appropriate, unless described otherwise above.Moreover, many modifications may be made to adapt a particular situationor material to the teachings of the invention without departing from theessential scope thereof. One skilled in the art will readily recognizefrom such discussion, and from the accompanying drawings and claims,that various changes, modifications and variations can be made thereinwithout departing from the spirit and scope of the present teachings asdefined in the following claims.

1. A growth control device comprising: a bone plate having a stepped profile defined by a first level, a second level and an intermediate ramp connecting the first and second levels, the first level including a first threaded hole for receiving a first bone fastener, the second level including a second threaded hole for receiving a second bone fastener, the bone plate including a proximal pair of side female notches, a distal pair of side female notches, a proximal guide hole and a distal guide hole.
 2. The growth control device of claim 1, further comprising: a holding device including first and second pivotably coupled arms, first and second legs extending from the corresponding first and second arms, a guiding bore defined between the first and second legs, and a curved split slot shaped to receive one of the proximal or distal ends of the bone plate, the split slot defining a split hole coextending with the guiding bore.
 3. The growth control device of claim 2, further comprising a guide wire, the guide wire passing through the guiding bore, through the split hole and through one of the proximal or distal holes of the bone plate, when the corresponding proximal or distal end of the bone plate is received in the split slot of the holding instrument.
 4. The growth control device of claim 3, further comprising a pair of male notches extending from a lower surface of the split slot perpendicularly to the lower surface, the pair of male notches shaped to be received in the corresponding female notches of the bone plate when the bone plate is held in the slit hole of the holding device.
 5. The growth control device of claim 4, wherein the bone plate includes a threaded third hole through the intermediate ramp.
 6. The growth control device of claim 5, further comprising an extractor having a distal end threadably couplable to the third hole of the bone plate.
 7. The growth control device of claim 4, further comprising a targeting device including a support plate, a support post passing through the support plate and having a distal end threadably engageable with the third hole of the bone plate, and a tubular drill guide passing through the support plate and having a maximum angle of angulation of about 16 degrees relative to the support post, the drill guide couplable with any one of the first or second holes of the bone plate.
 8. The growth control device of claim 1, further comprising first and second washers unitarily integrated with the bone plate and surrounding the first and second holes on a bone engaging surface of the bone plate.
 9. The growth control device of claim 9, further comprising first and second bone fasteners, each bone fastener having a substantially spherical head and capable of angulating relative to the bone plate when received through a corresponding first or second hole of the bone plate.
 10. A growth control device comprising: a bone plate having a stepped profile defined by a first level, a second level and an intermediate ramp connecting the first and second levels, the first level including a first threaded hole, the second level including a second threaded hole, the bone plate including a proximal pair of side female notches, a distal pair of side female notches, a proximal guide hole and a distal guide hole; first and second bone fasteners receivable in the first and second holes and angulatable relative to an axis substantially orthogonal to the bone plate within a cone of angulation; a holding device having first and second arms pivotable relative to one another, and first and second legs extending from the first and second arms, the first and second legs having first and second distal ends defining a curved split slot and a pair of male notches extending from a lower surface of the split notch, the first and second male notches engaging the first and second female notches when one of the proximal or distal ends of the bone plate is held in the curved split slot.
 11. The growth control device of claim 10, further comprising a second bone plate having first and second threaded holes for bone fasteners and a third hole in an arched intermediated portion between the first and second holes.
 12. The growth control device of claim 10, further comprising a targeting device including a support plate having a plurality of openings, a support post passing through the support plate and having a distal end threadably engageable with the third hole of the bone plate, and a tubular drill guide passing through the support plate and having a maximum angle of angulation of about 16 degrees relative to the support post, the drill guide couplable with any one of the first or second holes of the bone plate.
 13. The growth control device of claim 10, further comprising a bone plate extractor, the extractor having a distal end including a threaded portion, a cutting flute and a curved tip with a non-invasive radius.
 14. The growth control device of claim 10, wherein the first and second holes define a substantially spherical surface.
 15. The growth control device of claim 10, wherein the first and second legs of the holding device are shaped to define a guiding bore terminating at a split hole defined at the distal ends of the first and second legs.
 16. The growth control device of claim 15, further comprising a guide wire passing through the guiding bore, the split hole, and one of the end holes of the bone plate when the bone plate is held by the split slot of the holding device.
 17. A growth control device comprising: a plurality of bone plates of different sizes, each bone plate having first and second threaded holes and an intermediate portion between the first and second holes, the intermediate portion having a third threaded hole, the plurality of bone plates including at least one stepped bone plate having an intermediate portion in the form of a ramp, and at least one arched bone plate having an intermediate portion in the form of a curved arch.
 18. The growth control device of claim 17, wherein each of the bone plates includes first and second washers unitarily attached to the bone plate and surrounding the first and second holes on a bone engaging surface of the bone plate.
 19. The growth control device of claim 18, further comprising a plurality of threaded bone fasteners, each bone fastener having a head, the head angulatably received within one of the first or second holes, such that a longitudinal axis of the bone fastener can form an angle in the range of about 0-16 degrees relative to an axis perpendicular to the bone plate.
 20. The growth control device of claim 17, wherein each bone plate includes a proximal pair of side female notches, a distal pair of side female notches, a proximal guide hole and a distal guide hole 